Tiger Lily by Abigail Drake

Lily Madison’s problems began the day her life ended. After getting saved from a watery grave, she wakes up in a hospital surrounded by a herd of naughty ghosts. Most of them look like fuzzy blobs, but one is not blobby at all. He’s a very hot, very annoying dead guy named Nick.
Before she died, choosing a prom date was her biggest dilemma. Now she’s being stalked by specters and haunted by hooligans. Lily begins to doubt her own sanity, until she finds out a Goth girl named Zoe can see the blobs, too.
With the assistance of Zoe and Mr. Wan, the manicurist who almost killed her, she must get Nick and the other ghosts back where they belong or the whole world could be in terrible danger. But she’s grown to care for Nick, and if sending the ghosts back means saying goodbye to Nick forever, Lily isn’t sure she’ll be able to let him go.